Evaluating the impact of spatial resolution on surface water mapping in the Colorado River Basin
Patricia Puente1 and Laura E Condon2
1Department of Mathematics - Program in Applied Mathematics
2Department of Hydrology and Atmospheric Sciences
University of Arizona, Tucson, AZ
Understanding surface water dynamics is crucial for assessing hydrologic variability and water availability in the Colorado River Basin (CRB). Advances in remote sensing have enabled the mapping of surface water extent using satellite imagery, particularly Landsat (30-meter resolution) and Sentinel-2 (10-meter resolution). Landsat provides a longer historical record, while Sentinel-2 offers finer spatial resolution but a much shorter temporal history. Despite these trade-offs, the differences between these datasets remain understudied. This research examines how Landsat and Sentinel-2 derived water extents compare across the CRB and explores factors that explain their differences. Specifically, we assess the spatial patterns of agreement and disagreement, determine whether Sentinel-2 systematically maps greater water extents due to its finer resolution, and investigate whether discrepancies are concentrated in specific hydrologic or geographic regions. Additionally, we evaluate the detectability of different stream orders in each dataset and analyze how their classification as seasonal or permanent water varies. By identifying the strengths and limitations of each dataset, this study provides insights into the applicability of remote sensing tools for monitoring surface water dynamics in complex river basins like the CRB.